This invention relates to a device for decreasing side stream smoke when smoking a cylindrical tobacco product typically a cigarette, a cigar or the like. Since cigarettes are most abundantly used, the device of this invention will be described in connection with the cigarette.
When smoking a cigarette, a primary smoke current inhaled by the smoker and a secondary or side stream smoke current generated at the burning point are produced. In a normal smoking condition (smokes for two seconds in one minute, and 35 ml of smoke is inhaled) the quantity of the side stream smoke is larger than that of the primary smoke current, and it has been noted that the quantity of injurious substances contained in the side stream smoke current is larger than that contained in the primary smoke current.
For example, in page 75 of Hirayama and Namiki's text book of the title "Smoking Medical Science" published by Kodansha, in Tokyo, the ratio of the injurious substances contained in the primary and side stream smoke currents is described as shown in the following table I.
TABLE I ______________________________________ injurious substances side stream smoke/primary smoke current ______________________________________ tar 2.1-3.4 nicotine 1.8-2.8 benzopypen 3.9 carbon monoxide 4.7 ______________________________________
In recent years the injuriousness of smoking has became a social problem. Of course, smoking is injurious to the smoker himself, but the injuriousness to nearby persons is mainly caused by the side stream smoke. However, no expedient has been made for preventing generation of the side stream smoke.
Contamination of air due to the side stream smoke can not simply be prevented by mere ventilation with surrounding air. A passive measures, no smoking times, no smoking cars and no smoking rooms are now being adopted.
Generally stating, smoke is produced by combustion of a substance at a burning point. When the substance burns, in some cases no smoke is generated, but invisible gas is generated. Combustion is generally defined as a chemical reaction occurring when a substance is oxidized. Among substances, there are substances containing oxygen and substances that do not burn unless oxygen is supplied thereto from outside. In the case of a cigarette, most of the oxygen necessary for the combustion is supplied from outside.